
#[cfg(test)]
mod tests {
    use std::fs::read_to_string;
    use std::io::Result;

    fn read_and_transform_to_uppercase(file_path: &str) -> Result<String> {
        let contents: String = read_to_string(file_path)?;
        Ok(contents.to_uppercase())
    }

    #[test]
    fn test_file1() {
        match read_and_transform_to_uppercase("example.txt") {
            Ok(contents) => println!("File contents:\n{}", contents),
            Err(e) => println!("Error reading file: {}", e),
        }
    }

}